But in his first major policy speech as President Barack Obama's No. 2, Biden also declared the U.S. open for talks with Iran and Russia to repair relations. And he reached out to the world with a promise that the Obama administration will work with allies to solve global problems.

"We will draw upon all the elements of our power — military and diplomatic, intelligence and law enforcement, economic and cultural — to stop crises from occurring before they are in front of us," he told the gathering in his 25-minute address.

The much-anticipated speech got high marks from world leaders in the audience at this annual security conference.

"I think Vice President Biden came to Munich today in a spirit of partnership," British Foreign Secretary David Miliband told AP Television News. "I think he set an ambitious agenda with big goals and high objectives, and he called and challenged us to work with him. I think that's the right spirit."

While Biden's speech was short on details of emerging Obama administration policies — including its plans and ambitions for Afghanistan — his remarks set a tone of partnership in contrast to what some allies saw as a more bullying posture by the previous administration.

"We'll work in a partnership whenever we can, and alone only when we must. The threats we face have no respect for borders," Biden said. "We'll engage. We'll listen. We'll consult. America needs the world, just as I believe the world needs America."

Iranian leaves before Biden's speech
On Iran, Biden said the U.S. will strive to act preventively and avoid having to choose between the risks of war and the dangers of inaction. And he said if Tehran gives up its nuclear program and stops backing terrorists, there will be meaningful incentives.

He said the U.S. continues "to develop missile defenses to counter a growing Iranian capability, provided the technology is proven and it is cost-effective."

During much of the morning, Iranian parliamentary speaker Ali Larijani was in the room. But according to a participant inside the meeting, Larijani left the room during a break and did not return for the Biden address. The official spoke on condition of anonymity because the official was not authorized to speak about Larijani's activities.

There is no indication yet that Biden and Larijani will meet during the conference.

Biden, who also met privately with a number of world leaders, including top officials from Russia, France and Germany, told allies that they will be expected to share the burdens of fighting extremists and bolstering weaker governments and poor nations.

"America will do more; that's the good news," said Biden. "But the bad news is America will ask for more from our partners."

While President Barack Obama has said the U.S. is ready for direct talks with Iran, Biden's comments made it clear the U.S. is not willing to completely discard the stick, despite early warnings from Tehran.

His comments came a day after Larijani sternly declared that the Obama administration must admit past wrongs before there can be reconciliation. The old "carrot-and-stick policy must be discarded," he said, alluding to Western threats and offers of rewards to coax Iran to give up nuclear activities.

Tehran insists its nuclear aims are peaceful.

Reaching out to Russia
Reaching out to close another rift, Biden said it's time to repair relations between the U.S. and Russia, and the two should cooperate to defeat the Taliban and al-Qaida.

"It's time to press the reset button and to revisit the many areas where we can and should be working together with Russia," said Biden. Yet, he added that the U.S. will continue to have differences with Moscow, including opposition to its efforts to carve out independent states in Georgia.

Biden's comments come just days after Kyrgyzstan announced it will shut down American access to the Manas air base, which the U.S. uses to resupply troops in Afghanistan. The decision came when Kyrgyzstan's president was visiting Moscow, hours after securing more than $2 billion in loans and aid from Russia.

"The tonality was rather encouraging. It was really a serious call to restart U.S. foreign policy — including, clearly, Russian-American relations," said Konstantin Kosachev, head of the international relations committee in Russia's lower parliament house. Kosachev spoke on state-run Vesti-24 television.

On another topic, Biden told the leaders that the U.S. needs their help in taking the detainees now held at Guantanamo Bay, Cuba.

He repeated Obama's vow that the U.S. will adhere to its values, not torture, and will close the detention center at Guantanamo that has spurred such criticism from European allies.